The extracellular matrix (ECM) plays a key role in health and disease, and changes in ECM are observed in arthritis, diabetes, atherosclerosis and cancer. Prevention or therapy for these diseases will be dependent on a knowledge of cell interactions with the ECM. This process is in part regulated by growth factors that affect the synthesis and turnover of ECM via regulation of proteases and perhaps enzymes such as glycosyltransferases (GT) that are involved in the synthesis of matrix molecules. The long-term goal of this project if to understand the molecular mechanisms that mediate cell migration through the ECM. This is a dynamic process that required integration of cell adhesion, growth factors and proteases. In this proposal we focus on the migration of B lymphocytes through ECM because this is an important process in both normal immune function and in the maintenance of chronic inflammation and tumor cell invasion. The group involved in this pilot project is in a unique and excellent position to examine this process because: 1. We have an excellent model system using cell lines that show differences in their ability to migrate into ECM, and their ability to migrate correlates with the expression of the cell surface proteoglycan, syndecan; 2. We have expertise in the area of growth factors, especially TGFBeta, and can readily determine how various levels of this growth factor affect the synthesis and turnover of the ECM components and other chemotactic cytokines in migrating and non-migrating cells; 3. We have developed a number of specific photoaffinity probes to identify and quantitate some of the key enzymes (GT) that participate in the assembly of the heparan sulfate chains of the proteoglycans; 4. We have the technology and expertise to determine how various proteases are involved in cell migration in ECM and how growth factors affect their expression and activity. We also have purified a key metalloprotease to homogeneity and have molecular probes for this protein that will enable us to determine levels of mRNA and activity for this protein. Thus we can develop a comprehensive understanding of the molecular mechanisms that mediate cell migration through the ECM by defining how cell adhesion, growth factors and proteases act in concert during cell migration. This group of young and enthusiastic investigators will work closely with each other and interact regularly to help each other achieve the goals of this project. The overall goal will be to turn this grant into a program project or into interacting R)! grants. The project will be overseen by an Advisory Committee of highly qualified, research oriented senior faculty who will mentor the junior faculty and help them prepare competitive research grants.